1. Field of the Invention
The present invention relates to an optical lens, an optical module having the optical lens, and a backlight assembly having the optical lens.
2. Description of the Related Art
A display device converts an electric signal processed by an information processing device into a visible image. Examples of display devices include a cathode ray tube (CRT) apparatus, a plasma display panel (PDP) apparatus, a liquid crystal display (LCD) apparatus, an electro-luminance (EL) apparatus, etc.
The LCD apparatus displays an image by using electrical and optical characteristics of liquid crystal. The LCD apparatus is lightweight, has a low driving voltage, and low power consumption, etc. Therefore, the LCD apparatus is used in various fields.
An LCD apparatus displays an image by using a separate light source. In other words, the LCD panel does not emit light by itself. Therefore, the LCD apparatus requires a light source that provides an LCD panel with light.
Generally, a conventional LCD apparatus employs a light source generating a white light, such as a cold cathode fluorescent lamp (CCFL) or a flat fluorescent lamp (FFL). Recently, an LCD apparatus employing light sources that emit three basic colors separately has been developed in order to enhance color-reproducibility. The LCD apparatus employs, for example, a point light source such as a red light emitting diode (red LED), a green light emitting diode (green LED) and a blue light emitting diode (blue LED). Red light, green light and blue light generated by the red, green and blue LEDs, respectively, are matched with color filters, so that the color-reproducibility is enhanced.
However, in order to get uniform luminance by using the LEDs, the LCD apparatus employs a plurality of LEDs which increases the manufacturing cost thereof.